1. Field of the Invention
The present invention relates to the technical field of agricultural machinery and relates in particular to the field of implements of the mower or mower-conditioner type. The present invention is more specifically aimed at a mower or mower-conditioner intended to be attached to the lifting system of a tractor. Such implements are generally equipped with a cutting mechanism which folds vertically upward or longitudinally backward for transport by road. The implements in question may therefore be moved into a transport position. The cutting mechanism of an implement such as this is preferably able to pivot between a transport position and at least one work position. In what follows, allusion will be more specifically made to a disk mower, but the invention is not restricted to this particular example of mower. Other implements, such as drum-type or reciprocating mowers, would not be departing from the scope of the present invention.
2. Discussion of the Background
The production of a mower comprising:
a cutting mechanism which, during work, extends transversely to the direction of work, PA1 a hitching structure intended to be connected to a motor vehicle, PA1 a carrying beam connected, on one hand, to the cutting mechanism by means of a first articulation, the axis of which is directed forward, and, on another hand, directly or indirectly to the hitching structure by means of a second articulation, the axis of which is directed forward and of a third articulation, the axis of which is directed upward, which allows the second articulation to pivot with respect to the hitching structure, PA1 positioning means acting on the carrying beam to allow said carrying beam and the cutting mechanism to be moved simultaneously between at least one transport position and one other position, and vice versa, by pivoting of the carrier beam and of the cutting mechanism about the axis of the third articulation, and PA1 a lifting member acting on the carrying beam to allow said carrying beam and the cutting mechanism to be moved simultaneously between a work position and a maneuvering position, is known.
Specifically, this known mower can be placed in a transport position in which the carrying beam and the cutting mechanism are pivoted horizontally backward, using positioning means.
The lifting member consists of a hydraulic ram mounted between the hitching structure and the carrying beam, so as to raise the cutting mechanism for headland maneuvers. The tractor lifting system supporting the hitching structure therefore remains in the same position with respect to the tractor. For cutting operations, the lifting member allows the cutting mechanism to be rested down on the ground. The cutting mechanism is then in a work position.
Such known mowers seem to be fairly sensitive to the unevennesses of the ground over which the tractor is moving with the cutting mechanism in the raised maneuvering or transport position. The jolts and abrupt movements of the cutting mechanism may be transmitted directly to the hitching structure and to the carrying beam. Certain articulations and parts are therefore very highly loaded and this often gives rise to damage or premature wear, especially when the mower is in the transport position.
It is also known practice, from document EP 0 880 879, to produce a mower comprising a hitching structure connected to a motor vehicle by means of an upper hitching point and two lower hitching points. One of the lower hitching points is connected to a device which allows the hitching structure to be moved with respect to said lower hitching point. The device, in this specific instance a hydraulic ram connected to a nitrogen chamber, allows the mower to be moved from a work position into a raised position and vice versa. The device described also makes it possible to achieve damping when the mower is in a raised position. By contrast, this damping function is no longer fulfilled when the mower is in the transport position.